Fred and George and the Marauder's Map
by the-ravenclaw-writer
Summary: The Weasley twins stumble across an interesting piece of parchment...
**AN: This is based off a prompt that I saw on Instagram also I really love the Weasley twins (who doesn't?) and they reminded me of Sirius and James a bit so I though it'd be cool to get them to 'meet'. Plus I've always wondered how they figured out 'I solemnly swear I'm up to no good'.**

 **Disclaimers: I don't own anything in the Harry Potter universe**

* * *

"Hey Fred! Look what I found!" Fred looked up from inside the breadbin to where his brother was standing. George was holding a folded parchment, grinning stupidly, and Fred Apparated to him – despite the distance being less than ten feet.

"Oi let's see – what's that?" He made to grab the parchment, missing it by inches as George swiftly moved it out of his reach.

"Ah ah ahh! Not yet little brother – we're still in the kitchens, and as much as the house elves love us, I doubt they'd miss telling old Dumbles about _this_!" Fred tapped the side of his nose, and George huffed in exasperation.

"But what _is_ it? You have to tell me; we're twins! Anyway, don't call me 'little brother', mum said we were born at EXACTLY the same time –and even so, if we weren't, there's no possible way we'd ever know who was older. Even mum can't tell the difference! Remember that time when Ginny took Charlie's broom and-"

"Now isn't the time, _little brother_ , let's just get to the common room and then we can decide what to do with it." George Apparated as Fred leapt for him, and the latter found himself crashing into the stool George had just been standing on. The sound of the collision and Fred's annoyed shout of "Ow!" had two house elves popping into the room – but before they could identify him, the first year had Apparated away.

"What is your _problem_?" George didn't turn around at his brother's sudden arrival, nor did he respond to his question (although he probably wasn't listening).

"Oh hey Fred. Do you know what the password is? The Fat Lady isn't giving me a clue- what?" He protested in response to her tuts. "It's not my fault that we get so much homework that I can't remember one word to get past you!"

"You should take that up with the Headmaster, boy. Don't moan about your workload to me!" the Fat Lady huffed once more, before turning back to her book.

Fred was grinning as he winked at his brother and turned so that he was facing the painting. He put on a false sincerity and held his hands as if in prayer.

"I'm sorry for my brother's scandalous behaviour – I agree with you, oh beauteous Fat Lady, how dare he speak to such a painting! What offense you must feel, having been disgraced by such a lowly student. First year Gryffindor, and already as cheeky as anything! How must you feel, poor woman? I can only _begin_ to imagine the-"

"Alright that's quite enough. And I must say, although your brother's behaviour was scandalous indeed, it wasn't half as bad as some of your house's previous inhabitants. Ooh, the stories I could tell!" She took a breath and the twins looked at each other, and in that moment it was as if they had mastered Occlumency.

 _Fred._

 _George._

 _You can see what's coming can't you?_

 _I can. Shall we run and risk never being allowed past the goddamn painting again?_

 _I would, but I really want to see what this parchment holds._

 _Of course! You know, George, I forgot we had that! And of course we need the privacy of the dorm, of course!  
Fred._

 _OF COURSE._

 _OF COURSE my ass, Freddy. We have more pressing issues. It has begun. Better look like we're listening._

The truth was that growing up as twins in a small house with plenty of mischief to cause and plenty of other family members to annoy, the boys had formed a special kind of brotherhood – one might say it was similar to Occlumency, bar the invasion of another's mind.

"… them – a boy, as one might expect – who disrespected me thoroughly! He used to try and court me - and I must say, although he had lovely black hair and a grin that made girls' hearts throb (of course I only know this because the gossiping girls of Gryffindor giggled about him), I am a painting! And I have been around longer than any of the students in this school! I know all their tricks! The courting boy had three friends you know; only one of them always knew the password. One! Anyway, courting boy had a friend with glasses, who would …" By this time, Fred and George had sat down on the floor and were leaning against the wall, heads in hands. One of them – the Fat Lady couldn't tell which – leaped up suddenly and pointed a finger at the painting.

"FLIBBERTIGIBBET!" He shouted, interrupting the Fat Lady, who spluttered and lifted a hand to her chest, outraged.

"How dare you, boy! I would personally come out of this blasted frame and give you a good talking to, if you hadn't already- wait! Ho! I see now - flibbertigibbet is the password through my door. Well I grant you this," she gestured as though showing off what was in her painting, "Entrance. To the Gryffindor Common Room." The painting swung slowly backwards and the twins stepped quickly through the hole, ignoring the protests of the Fat Lady behind them.

The Common Room was busy – as it always was in early December, when it was too cold outside for the younger players to play Quidditch (meaning all the Quidditch players from fourth year and below were huddled around the fire discussing game tactics), and most of the other outside extra-curricular clubs were closed (Herbology help sessions were held in the greenhouses, same as the lessons, except the students had access to a wider range of magical plants and Professor Sprout was more willing to teach – after all, these children had come to learn because they _liked_ the subject, not because it was compulsory).

Silently agreeing that the room was too full to talk about private matters, Fred and George wove their way through the clusters of their housemates and scuttled up the stairs to their dormitories, turning left at the top of the winding staircase into the first year boys' room.

Luckily the three other boys who shared the room with the twins were out – probably in the common room, George reasoned, as he has seen the distinctive blue hair of Jack (who was a rebellious teenager and dyed his hair a different colour every week with magic), and where Jack was, there his two minions – William and Tomas – resided.

"Right." Said Fred, climbing into George's bed. "Let's have a look at that parchment then."

"Close the bed curtains after me, we don't want the trio seeing and grassing us up." George did a running jump into the bed and bounced lightly. Fred slid the curtain along the frame and settled back down, facing his brother with his legs crossed, cracking his finger knuckles. The parchment was placed in between them.

"You do the honours, brother dearest." George gestured and his twin carefully unfolded the sheet, breaking the red wax seal.

"'Dangerous items.'" He read. They were silent for a moment until it dawned on them – simultaneously, it seemed – what they had found.

"George!" Fred looked up at his brother at the same time he said, "Fred!"

Grins spread across their faces and they bounced gleefully on the bed, and clasped each other's hands in joy.

* * *

Argus Filch rubbed his forehead and sighed. Another day had passed, and he had once again completed one of Albus Dumbledore's lists- at least, to the best of his squib ability. He resented it, but there was nothing he could do, and he should know – he'd tried everything.

He stood up, gathering his papers and sorting them into the labelled drawers in the desk. His cat, Mrs Norris, meowed quietly, and Filch felt his heart tug – he could tell she was tired (one forms a mutual understanding with one's cat after so many years) and so he quickly checked his tidy desk for anything he might want to take down to his room, before calling for Mrs Norris to follow him.

He pulled a lever underneath the desk which opened up the wall behind it. Filch liked to pretend that he was doing magic when he pulled that lever, and he'd sometimes turn around and point his wand – gifted to him by Mr. Olivander when he was a boy – and mutter one of the few spells he knew (but even those spells were the ones he had overheard students casting in classrooms – not that he'd ever admit to listening in to _any_ lesson being taught at Hogwarts- it was his special way of feeling included at the school).

The wall closed up behind him and he walked down the winding staircase to his living area, Mrs Norris by his heel. He put the torch in its holder and sat on the bed, taking his shoes off. The cat curled up next to him, and he reached out and scratched behind her ears; she purred loudly and bent down to kiss her softly.

After he'd changed into his striped pyjamas and had finished his nightly routine – reading two chapters of a selected book, brushing Mrs Norris' coat down, and drinking a glass of hot milk – he hobbled over to the torch holder and put the light out.

* * *

"This is quite possibly the best idea you've ever had, George, my chum pal chum buddy chum friend brother twin-" His whisper was cut short by a thump, and Fred winced in pain.

"Would you _stop_ calling me that? Otherwise I might have to resort to calling you what our Ginny calls us, you know, h-" This time it was George who got thumped, and who winced in pain.

"Evens?"

"Evens." They arrived at Filch's office, and both of them fell silent. Hands motions and spy-like movements had been perfected between the two; playing spies was a favourite – and they swiftly and silently opened the large door (any other witch or wizard could have used _alohomora_ to unlock it, but the two ginger-haired twelve year olds preferred the muggle method of stabbing the lock vigorously with a piece of wire).

They crept inside and used _lumos_ to see around them; not that there was much to see- the office was relatively tidy, with only a few stray pieces of parchment softly moving against the draft that had occurred with the open door.

There was a large desk at the back of the office, which had a wardrobe on either side – the one on the left labelled _D.I_ and the other: _H.I._

"Hey Fred," George said, looking at the two wardrobes, "what do you make of this?" His brother lifted his hand to see better, and with two _lumos_ spells protruding from the ends of their wands, the boys could clearly see the engraved letters on the furniture.

"Didn't that parchment have 'Dangerous Items' written on it?"

"Oh how clever!" George's voiced oozed with sarcasm. "Maybe you could use that flawless initiative to help us pass exams? But yes, my chum pal chum buddy chum friend brother twin friend-" For the third time today, a thump was passed between them.

"Okay, alright, I deserved that. Open the cupboard." Fred made a face at his brother.

"It's called a wardrobe, dimwit. They're wardrobes. You open the _wardrobe_ labelled H.I., I'll get the other wardrobe."

"Do you want to say wardrobe again?"

"Fuck off George."

Ten minutes later, and Fred's never-ending-bag was almost full with items from the Dangerous Items closet.

"George this bag is supposed to be never ending. How is it that I can see the last three items I put in? This is a fault, brother, and I suggest we demand a refund." Fred reached into the bag – which on the outside was about the size of a small handbag – and pulled out a blank parchment.

"This, for instance- why do we need this? It's blank!" George shook his hand and tutted solemnly.

"Fred, my chum pal chum buddy chum friend brother-" (Fred took a deep breath), "if Filch our dearest put this seemingly blank parchment into an assortment of _dangerous items_ , it can't _really_ be _blank_ , can it? There must be something _very_ interesting on this-"

"George my love can you _please_ stop putting _emphasis_ on _specific words_?" George chuckled and Fred's expression changed from annoyed to that holding a cheeky grin.

"Let's go; we've cleared out the dangerous items pile, and the other one looks as though Filch has just confiscated stuff for the sake of it. In fact, I bet the H.I. stands for harmless items. Or heavy items. Or handy items."

The boys continued coming up with ideas for what H.I. could've stood for as they walked back through Hogwarts and up into their dorm room.

"Right then Fred, let's empty this bag." George grabbed the handbag and tipped it upside down, and for a moment there was nothing but a sound similar to that of waves crashing. Then the bag emptied itself.

A while later and they had finally sorted out what they definitely wanted to keep from the pile, and what they had decided to 'gift' McGonagall in their next Transfiguration lesson.

"Blimey George, look at these!" George looked up from his pile to what Fred was holding – two oddly shaped cubes with feathers and glitter layering the sides.

"What? Fred they are nothing; check this out." He held up the blank parchment to his brother and told him to open it.

"George, I know you find it hard to believe, but this paper is about as interesting as Percy – on a bad day."

"No you idiot, ask it to let you see what's inside." Fred gave his brother the look, before complying.

Tapping the parchment, he said, "Can I see what secrets you hold?" With a voice that could not be interpreted in any other way than boredom and disbelief. George sighed loudly and snatched the blank sheet back.

"You have to do it like you mean it. I swear, there are people that talk back. It's great! You just gotta believe."

"Sorry George, I forgot you were Peter Pan." Fred muttered, but watched his brother suspiciously all the same, who tapped the paper like he had done previously, and greeted it formally.

Words erupted on the paper, as though someone was writing on it.

 _Messrs. Moony, Wormtail, Padfoot, and Prongs would like to respond to such a formal greeting with a warm welcome._

Delighted, George tapped the paper again, asking,

"What purpose does this parchment serve?"

The words faded away as he spoke, but in response to the boy's question, four different handwritten lines appeared, as though four people had replied.

 _Mr. Moony regrets to inform the holder that without identification, he cannot reveal any secrets._

 _Mr. Wormtail would like to point out that the holders should remember where they found this parchment._

 _Mr. Padfoot would like to compliment the holder (and his companion) on their luscious ginger locks._

 _Mr. Prongs agrees with Mr. Padfoot._

Fred laughed out loud, shuffling closer to his brother to see what else the strange article had to offer.

"Well go on then! Tell it who we are!" George grinned eagerly and tapped the paper again.

"Messrs. Moony, Wormtail, Padfoot, and Prongs, we are the twin brothers Weasley – Fred and George." He looked anxiously at his the boy next to him, wondering if that was too much of a formal way to introduce themselves.

 _Mr. Moony would like to thank the holders for such a polite introduction, and would like to point out that their mother, Molly, is a good friend of his._

 _Mr. Wormtail seconds Mr. Moony, and asks if their father is Arthur Weasley._

 _Mr. Padfoot laughs at Mr. Wormtail's question, and would like to point out to both Mr. Wormtail and the Weasley brothers that if Molly was their mother, Arthur Weasley_ _would have to be their father._

 _Mr. Prongs clips Mr. Padfoot's ear for being so rude around Fred and George Weasley._

 _Mr. Moony would like to apologise for this companions' behaviour._

The boys were still laughing by the time the writing faded, but Fred quickly sobered up once he realised what they had said.

"Wait if mum is their friend, doesn't that mean that they'll tell her what we've been doing? We stole from Filch's office and now we're looking through said stolen goods." George stared incredulously at his brother.

"Do you know, Fred, I think that's the first time you've shown any moral problems with our mischief? Anyway, these four are stuck in this paper; they're not likely to get out any time soon."

Fred blushed lightly, but the colour soon left his face as he came up with another question for the parchment.

"Mr. Moony mentioned secrets earlier – could you be so kind as to tell us what secrets you hold?"

There was a long pause before scruffy handwriting appeared once more.

 _Mr. Wormtail apologises for the wait, but Messrs. Moony, Padfoot, and Prongs are having what one might call a conference._

The words faded quickly, and the twins glanced at each other – another not-Occlumency type situation was occurring. It ended before any major concern could crop up, though, as the parchment 'spoke' once more.

 _Messrs. Moony, Wormtail, Padfoot,and Prongs are sorry to say – but feel it is their duty to – that this parchment is guarded by a password. Only those who correctly guess the password have access to the information we conceal._

"Well that was bloody great." George announced. "All that idle chitchat and we find there's a _password_ we have to crack. What a waste of time."

"No, George, don't you get it? If there's a password, there is going to be some good things inside – otherwise what's the point?" Fred raised his eyebrows, and George gave in.

"Fine, but if it takes longer than an hour, I'm going to bed. It's already half eleven, and we have Charms tomorrow. You know what dear old Filius is like if we're late." They debated for a bit what the next best course of action would be, before deciding on asking the four for a clue.

 _Mr. Moony asks first that you promise to do bad things with the information inside._

"'…promise to do bad things?' What kind of things? What if it's actually a list of ways to kill people. George what if Filch labelled it dangerous because it actually _is_ dangerous?" Fred stared at his brother with wide eyes, who stared back with disbelief.

"Are you kidding? Have you even been reading what they've been saying? Do these four sound like the type to _kill_ people? Wait a minute… Frederick, have you gone soft? You were never like this before." George grinned mischievously. "Frederick Gideon Weasley, I never thought I'd live to see the day when you-"

"Hey! I haven't 'gone soft'!" Fred interrupted, faking outrage.

"Prove it." George's mischievous grin spread to his brother, and before they knew it, they were downstairs, and three second year Gryffindors were hanging by their feet from the Common Room ceiling, and upstairs again in a flash.

"Fine. You haven't gone soft. Now let's figure out how to crack this thing."

* * *

Half an hour later, with much pestering of Messrs. Moony, Wormtail, Padfoot, and Prongs, Fred and George Weasley weren't much closer than they were thirty minutes ago.

"So we know that it has something to do with promising to create chaos, right?" George nodded, and Fred continued. "And we've tried twenty-three different versions of 'I promise to create chaos', yeah?" George nodded again, and Fred continued. "But have we tried swearing at it? I mean, these four don't seem to be the type that speaks like they write – it doesn't sound very genuine, I mean." George looked up at him and nodded enthusiastically.

"So let's try cursing at them!" They snickered and pulled out the parchment.

Fred tapped it and they proclaimed loudly (and in unison),

"I promise to fuck shit up." Writing spewed out from the page in a flurry.

 _Mr. Moony would like to ask Messrs. Weasley why he thinks such foul language is necessary to accomplish mischief._

 _Mr. Wormtail would like to inform Messrs. Weasley that they are getting warmer._

 _Mr. Padfoot would like to high five Messrs. Weasley._

 _Mr. Prongs would like to have a pint with Messrs. Weasley as they seem like just his kind of people. As long as they solemnly swear it._

The responses had been getting more and more clue-filled, but the twins couldn't crack the actual password.

"Mr. Moony says 'necessary to accomplish mischief' and then Mr. Prongs says 'solemnly swear'." Fred muttered to himself. He scribbled down the two phrases on a spare bit of parchment that they had stolen from Filch's office.

"Hey what if we try 'I solemnly swear I'm gonna accomplish mischief'?" George suggested, and as soon as he had said it, the page in front of them filled with words again.

 _Mr. Moony would rather Messrs. Weasley were sure of their intentions to get up to no good, than to speak as though they are_ going _to._

 _Mr. Wormtail agrees with Mr. Moony and would like to point out that Messrs. Weasley must be up to no good, otherwise they wouldn't have this sheet in the first place. Also that Messrs. Weasley are warmer than ever._

 _Mr. Padfoot agrees with Mr. Prongs previous statement about a pint, and would like to second it._

 _Mr. Prongs advises Messrs. Weasley not to go anywhere_ near _Mr. Padfoot once he has had a few drinks._

"I like Padfoot and Prongs best." George declared.

"Me too; I bet they'd be a gallon of laughs to be with, but Moony and Wormtail are the only ones helping us solve the puzzle, so right now, I'm more inclined to them." He ignored his brother's expression, and continued. "Moony says that we need to be sure of being up to no good, and Wormtail repeats that phrase." George nodded and continued chewing a loaf of bread.

"Where'd you get that?" Fred asked, reaching for his own bit.

"It's from the kitchens earlier. I forgot about it 'til now." George ripped the remaining bit in half and gave his twin the bigger bit.

In between mouthfuls, he added, "Just like Prongs did with the solemnly swear bit. And then Wormtail told us we were getting warm." Fred agreed eagerly, scribbling notes down as crumbs of the bread fell from his mouth.

"Okay how about this?" He said, showing George the paper he had just written on. A smile crept onto their faces and they tapped the parchment, declaring,

"I solemnly swear I am up to no good."


End file.
